Concussions are scary. For those that don't know I hit a tree I while racing my bike head on at the end of November 2012 and just started to feel normal at the end of April. I thought I was fine in January but looking back now I clearly wasn't.
Don't mess with that injury. Rest 4x as much as you think you need to. It'll be a shorter recovery in the long run.
I'm still taking anti-headache medicine, 8+ months out, and that hasn't prevented all of them. This experience has been all about learning how to deal with the limitations that this injury leaves you with, possibly for life.
Also, I learned about what a great group of friends I have here in the cycling community in New England. Thanks to you all.